Popular Science Monthly/Volume 86/January 1915/Geological Methods in Earlier Days
|GEOLOGICAL METHODS IN EARLIER DAYS|
NEW YORK UNIVERSITY
WHILE reading discussions of modern field and office methods, published in Economic Geology, I became impressed with the feeling that some notes, historical and reminiscent, respecting conditions and methods of forty and more years ago, should be placed on record for the benefit of the younger geologists. The reminiscences are confined to my own experience, which, however, did not differ from that of contemporary workers.
Popular interest in natural history was quickened, early in the nineteenth century, by the formation of societies and the founding of museums. Efforts to secure cooperation by the central government were so far successful that surgeons accompanying exploring expeditions, in charge of army officers, were chosen as much because of willingness to act as collectors as because of medical skill. Very soon, natural history came to be regarded as, at least, lending dignity to an expedition’s work, so that an army-explorer looked upon his equipment as defective unless it included a naturalist; a report without an appendix or a series of appendices, discussing collections secured by the party, seemed to be painfully incomplete. After the first third of the century had passed, geology acquired some degree of popular respect as a practical science and it received recognition from the War Department. The making of geological observations became part of the duty assigned to the naturalist-surgeon. In almost every case, however, the work of the naturalist or geologist was merely incidental and his opportunity to obtain detailed information was limited.
In the later sixties, after the close of the Civil War, the War Department, through the corps of engineers, began exploration anew. Clarence King’s organization was under this Bureau, but he was not subject to military control in the field; his only hindrance was the pressure for results to prove speedy productiveness and to satisfy inquiring legislators that the field-work had not been merely a prolonged picnic. Somewhat later, an organization of the earlier or reconnaissance type was effected and was placed in charge of Lieutenant George M. Wheeler, who was endowed with extraordinary energy and with such physical endurance as to be a source of pain to all members of his party. In 1872, Wheeler became convinced that, without geological and other scientific contributions, his work would be incomplete, for Hayden had already loomed large on the horizon. The scope of the organization was enlarged and G. K. Gilbert, with E. E. Howell, was appointed, each being attached to a party as geologist. In 1873, there was farther enlargement and a party was formed to map and to explore about half of the mountain region of Colorado, with as much of New Mexico as possible, an area of not far from 30,000 square miles, containing much extremely complicated geology. J. J. Stevenson was assigned to this party as geologist. The party consisted of Lieutenant (now Brigadier-General, retired) W. L. Marshall, two topographers, three “scientific workers,” an imposing array of packers and an escort of 25 infantry soldiers, who were to serve as protection against Indians. There were some good men in this escort, but before the season was well underway, there seemed to be reason for supposing that the authorities at Fort Leavenworth had unloaded their guardhouse on us. Ninety six mules of varying temperaments completed the equipment.
The request for a large appropriation from Congress had been enforced by proof that the work of previous years had been done at an almost incredibly small cost per square mile—and the argument was effective. The work in 1873 was to be an improvement on that of the past but the importance of economical operation was not to be forgotten. The geologist received a small mountain aneroid, a clinometer compass, a pocket level and a hammer; the naturalist-surgeon was equipped with a Spencer carbine of large bore, that he might shoot birds and other small animals; the collector in botany had his presses; the youthful barometer-carrier had his burden strapped on his back; the expedition was ready to start. After a series of misunderstandings with the mules, one of which led to a stampede which startled the youthful city of Denver, the party set forth in single file, as is the manner of mules.
The geologists associated with the Wheeler organization had gained some experience in the field, chiefly in connection with the Ohio survey, and they had gone with Wheeler in search of a wider field of usefulness. The field of the Colorado party proved very useful to me, but very soon I had misgivings as to my usefulness in that field. It became evident very quickly that geography, not geology, was the objective, and that the important elements in equipment of a geologist for this work were a lively scientific imagination and ability to solve stratigraphic puzzles by intuition. There was no map and the topographer’s notebook was of little service. The direction of travel was determined by conditions, so that, without a map, one could not keep his bearings in the maze of valleys and canons. The topographer was always secure, as the expedition was for him, but the geologist was in constant uncertainty. If he saw a section, which might relieve his perplexity, he was in anxious concern, knowing that if he measured the section, the train would disappear and he might be as a man hunting the needle in a haystack. But he had to secure sections, he had to examine anomalous exposures, and afterwards he had to find the train. The conditions made for rapid movement when at work, for keenness of observation, for quickness of perception, for promptness in decision as well as for error in conclusion. The geologist learned to follow the track of the train, but the close watch for crushed grass or for fleeting footprints in sand prevented him from seeing important features during his hasty ride.
In comparing the work of the earlier days with that performed more recently, under better conditions and with the aid of the earlier reconnaissances, I have been astonished that so much, and the word is used advisedly, has endured the test of friendly as well as of unfriendly criticism. It is surprising that geologists, slung about as bobs on the tail of a topographer’s kite in a wholly unknown region, succeeded so well in gaining knowledge of the general structure; they failed only where they attempted detailed description or discussion. Maps were prepared slowly after the season closed and when the geologist received them, a year or more afterwards, they were a mystery. Streams followed wholly unsuspected directions; localities were in relations very different from those conceived when the work was in progress; in critical places the map was altogether unlike that drawn in the geologist’s mind. It was impossible to bring the imagined into harmony with the real, so that some portions were colored on the basis of a mental reconnaissance. Geologists attached to the Hayden survey were at somewhat less disadvantage because the work was primarily geological; but they were hampered very seriously in other directions. In those early days the importance of surveys was not recognized; in order to secure appropriations it was necessary to produce bulky reports referring to great areas; there was no time for careful work, yet several geologists associated with Hayden made remarkable studies and solved intricate problems. The Powell survey, because of the Major’s marvelous skill in manipulation of Congressional committees, was hampered much less, and the work done by Gilbert and by Dutton is of lasting importance.
Geological surveys in individual states were begun very early but, except in Massachusetts, they were short lived and on a small scale. The great surveys of New York, Pennsylvania and Virginia were begun in 1836. At that time, there were practically no geologists in the country; of those known as mining engineers, not more than five or six had received any geological training. The geological surveys were entrusted mostly to young men; Rogers of Virginia was 32; his brother in Pennsylvania was 28; in New York, Mather was 32, Vanuxem was 44, Emmons, 37 and Hall, 25. Among the assistants on the Pennsylvania survey were Lesley, 20, Hodge, 21, Jackson, 23, Haldeman, 24. The country in much of Virginia, Pennsylvania and Ohio, even in New York, was little better than a wilderness, eighty years ago; railroads were practically unknown and there were few graded roads; aneroids were mere toys and Locke had not invented his pocket level; there were no instruments except those of cumbrous size; boiling point thermometers were tried but they proved worthless; there were few maps and such as did exist were misleading. The young men, without previous training, without instruments of any sort, except a compass, and without maps, were thrown into the unexplored region. It has been my privilege to reexamine much of the area in which they labored. How they obtained their results passes comprehension; they carried the Bituminous section in Pennsylvania and Virginia with wondrous accuracy, though at times there were intervals of miles in which no exposures existed except along streams flowing through the woodland. It is easy now to discover inaccuracies in their work, for men can examine it, so to speak, with a microscope. These early geologists, for the most part, were men of gigantic intellect and noble integrity.
With the close of these surveys in 1842 to 1845, extended work came to an end. Some organizations were continued in a moderate way, but all except those of Illinois and New York were broken up by the Civil War, and there was no revival until the later sixties. Meanwhile the condition existing in 1836 had returned. Not more than 30 men survived who had been trained in field work; some of these had gone into special work as mining engineers, others were in enfeebled health, and others still were in positions less onerous and more remunerative than survey work. Probably not more than ten men were available in 1869, and several of those were attached to surveys not interrupted by the Civil War.
The Ohio survey, reorganized in 1869, had as its director the veteran Newberry, who, as a young physician, had entered the United States service during the Pacific Railroad explorations. As a lad he had collected fossil plants from the roof of his father’s coal mine in Ohio, and in later years he had studied paleobotany under Brongniart in Paris. His work as geologist, botanist and zoologist on the Pacific Railroad explorations was brilliant, but in importance was far excelled by his later geological work on the Ives and Macomb expeditions. Of his assistants on the Ohio survey, only one could be regarded as a professional geologist; the others were amateurs. Of the aids and co-workers, not more than three had done any field work and the most of us were wholly inexperienced. We were expected to succeed without help, as our predecessors had done; an area was assigned to each man and he was told to get at it. The state maps were good, but on a small scale; the general structure had been worked out by the Mather survey long before, and both Newberry and Whittlesey had published small outline maps; but, as far as details were concerned, the region was a terra incognita. Did we make blunders? We simply reveled in ignorance; we learned by making mistakes and by occasionally discovering some of them. We did not know for what to look, but we looked at everything, for everything was a revelation. Some of the worst errors in correlation were due to this. On my third day, while day-dreaming over what seemed to be a remarkable phenomenon, I lost hold of the section, and in crossing the divide committed an error which affected my work throughout that summer and the next. There was no opportunity for revision; the western method of reconnaissance prevailed and a line once covered was completed. The young men, who did the work for their expenses, gained a vast amount of knowledge but not much modesty; they had been found capable of doing a new type of work without assistance. The rod of correction was applied somewhat more than ten years later by Professor Edward Orton, Sr., but the application was made so gently, so courteously, that all of us were united in gratitude to the keen man who had harmonized conflicting observations and had corrected errors, but had administered no rebuke to the incompetent youths who had made them. Economically, the errors were unimportant as they were chiefly in correlation; the resources of state were described well and the observations were recorded honestly. A group of geologists were trained, who, under Orton during the third survey, knew for what to look, how to look for it and, better still, how to present their results.
The second survey of Pennsylvania was ordered by the Legislature of that state in 1874, forty years ago, and J. P. Lesley was appointed as director. Though a survivor of the first survey, discontinued more than 30 years before, he was still in the prime of his powers and, along certain lines, he was perhaps the ablest geologist in the country. But he had entered from the topographical side and all his work had been concerned with economic applications of geology. The survey had been ordered on an extensive scale that the mineral resources of the state might be determined in practical detail, so that it was necessary to publish prompt and somewhat voluminous reports in order to suppress recalcitrant legislators. In 1875 I was appointed geologist in charge of the southwestern district and entered upon the work with I. C. White as aid. It may be remarked in passing that, in state work, the geologist must contend with one serious cause of error which is unknown to the western explorer. Sleepless nights were rare during the western work, but in the civilized region, where one must live off the country, there is often the terror that walketh in darkness, which benumbs the geologist’s intellect and blinds his eyes during the day.
Thirty-five years prior to our advent, Henderson had completed his work for the first survey and had reached the conclusion that, owing to lack of exposure, the upper part of the section would never be worked out. During that interval there had been no change in conditions except that the region had been stripped of forest and numerous rude country roads had been made. There was no railroad, except at the extreme north; there were no extensive mining operations except on the Pittsburgh coal bed on the Monongahela River, and there were no records of oil borings except in the southeast corner where they were not needed. To add to the natural drawbacks, we were equipped with aneroids which were fearfully and wonderfully made. Lesley, unable to induce Becker to make a supply of high grade barometers, had procured a number of models to be tested. Those assigned to us were shaped like a hat box and were provided with vernier and other attachments, all of which had to be cared for at each reading, as otherwise the observation would be wholly worthless. Happily for us, our horses ran away one day; when the race was over and White’s horse had won, we discovered with grateful hearts that the barometers were ruined. Thereafter we used our own barometers, which proved to be fairly good.
As soon as we had passed beyond 100 feet above the Waynesburg coal bed, satisfactory exposures became rare—and nine tenths of Greene County, in which we had begun, was above that horizon. The only recourse was to examine every bit of rock that jutted out on a hillside. Sections were made everywhere, 5 to 100 or more feet long, but the longer ones had tormenting gaps which refused to be filled. Strange anomalies appeared, which cast doubt on tentative correlations; limestone was found where we expected variegated shale; streaks of coal appeared in what seemed to be wrong positions; sandstone was seen where there should have been a coal bed. Our work proved that these are not anomalies and the conditions are commonplaces to-day; but 40 years ago the continuity of deposits was a cardinal doctrine and all limestones were marine. Our conversion was slow but it came, and little by little we were able to piece the fragments together; the section was completed as far as possible and doubt remained respecting only a few horizons, which were not economically important.
It would have been well if several localities could have been re-examined; a number of errors would have been eliminated which now are so evident that any one can note them. Revision is very different from original work, and is a very simple matter. If the original observer has recorded his observations honestly, the reviser needs no especial acumen in order to discover the errors. If White and I had had the advantage, 40 years ago, of the hundreds of oil-well records made in the Greene and Washington district during the last 20 years, our work would have been a holiday jaunt; we should not have been compelled to spend so many dreary days in securing fragmentary sections or so many weary nights in trying to combine them. But there were no well records and there was no opportunity for revision. Too much time had been spent in Greene; there remained the larger county of Washington and a great part of Allegheny to be studied.
The problems in Washington, though different, were equally perplexing for a time. Exposures were better, longer continuous sections were secured, but new members came in while familiar ones dropped out. We were firm believers in variation of intervals between coal beds, but were not prepared for the variations which had been accomplished in the deeply buried portions of the section within northern Greene and southern Washington and which were revealed under an anticline in Washington. The imperfect record of a coal shaft reaching the Pittsburgh coal bed removed all doubts and filled us with intense respect for such records. The work in this county was not difficult as the section had been mastered; the especial burden being to cover the region in detail before snowfall, as the report must be ready for the printer before adjournment of Legislature.
During this season’s work our attention was concentrated upon correlation and economic questions; there was no time for studies concerning matters of purely scientific interest. So intent were we in consideration of those subjects that we neglected to make notes of features which are all-important in their bearing on problems relating to coal and coal beds. Having sinned in this way, it is not for me to cast stones at any one for a similar sin, provided it has been committed under similar conditions.
A serious difficulty encountered by geologists in the earlier work was the inaccuracy of maps. One illustration suffices. In Fayette and Westmoreland Counties of Pennsylvania, I made use of maps which the county surveyors regarded as the least inaccurate. Professor Lesley had done some geological work in those counties and had discovered defects in the maps, which disturbed him greatly. He chose worse maps, corrected some errors in them and transferred my outcrop lines to the new base. The creations were put on the stone and proofs were sent to me. A single glance aroused feelings too deep for utterance and the proofs were returned without change. No doubt many other geologists can relate a similar experience.
Geologists, entering on field work within the last score of years, know little of the difficulties attending exploration forty or more years ago, especially in coal areas, where the effort was to trace thin deposits throughout extensive areas; though exception should be made in favor of those laboring in similar areas at the far west, where dependence must still be placed on natural exposures. In by far the greater part of the country the structural geology has been worked out during more or less reconnoissances, so that when the reviser entered the field he found everything so simple that he was astonished that any one should have been perplexed and still more astonished that mistakes were made. The structure of the Elk mountains in Colorado is distinct and every feature stands out so sharply that a child in geology can read the story. But the case was very different before W. H. Holmes recognized in the crumpled mass of fragments merely a crushed, faulted fold and restored the original lines. The symmetry of the Jura mountains is the admiration of geologists, but the key to unlock its case of mysteries was not found until H. D. Rogers, fresh from his Appalachian studies, proved the simplicity of its structure. The older geologists made our geology. In most of the United States, Canada and Europe, the share of recent geologists is like that of workmen who fill up cracks in the walls and interior of a building and put on the finishing touches, that the edifice may be the better fitted to resist the ravages of time.
The writer is not of those who believe that the older days were better than these or that the geologists of half a century ago were superior to those of our own day. Such a conception would be arrant folly. But he is convinced that in some respects the work of too many geologists is defective and that the cause is not hard to find. The methods are too refined and dependence on them tends to make the process too mechanical. The older geologists had practically no appliances except their eyes, and comparatively few of them had more than a passing knowledge of topography. The contrast appears sharply in the reports. The writer, in endeavoring to ascertain conditions prevalent during deposition of coals in the United States and Europe, has examined carefully scores of thousands of pages in several languages, so that he writes feelingly. Within recent times the tendency has been to record chiefly such observations as have the accuracy of instrumental determination. Other matters seem to be unimportant; they are commonplaces, unworthy of record. Yet those commonplaces are the essentials of pure geology. Certainly, one is justified in asking that men who have only to revise, with the aid of later developments, the work of other men, should add greatly to knowledge in the province of pure geology. It is more than probable that the demand for economic facts dulls the vision for other things, as it did too often 60 years ago, but there is room for protest against continuance of the condition. One may be pardoned for expressing the conviction that the weird work of Land Classification for the United States is likely to be, as it were, a red-hot iron rod passed close to the eyes of probably the ablest corps of geologists this world has known.